1. Field of the Invention
The present invention relates to an on-vehicle radar device and a vehicle.
2. Description of the Related Art
Research has been conducted in recent years into areas such as collision avoidance, driving assistance, and automatic driving, utilizing technology that uses radar to detect objects around a vehicle. In the case of a car, the radar has conventionally been provided on the front nose. A high-frequency oscillator needs to be placed in the vicinity of an antenna and requires water and weather proofing measures, such as protection using a radome (i.e., a radio dome), to avoid wind and rain. Meanwhile, more sophisticated detection technology has also been developed, using both radar detection and camera images.
U.S. Pat. No. 8,604,968 proposes a radar-camera sensor in which a radar and a camera are housed in a single housing. The radar-camera sensor is mounted on the front windshield of a car forward of the rear-view mirror. The radar waves used are either vertically or horizontally polarized radio waves.
A multifunctional sensor unit disclosed as an external-field-of-vehicle recognizing apparatus in International Publication No. WO/2006/035510 also has an image capturing part and a transmission/reception part that are mounted on a single sensor mounting board. The multifunctional sensor unit is installed in the interior of the vehicle.
Radar waves are attenuated due to being reflected and absorbed by the front windshield if a radar device is placed in the interior of a vehicle. The glass shows a greater influence in the case where short-wavelength radio waves are used to improve the resolution of the radar. Also, the output of the oscillator cannot be increased because there are statutory regulations governing the output of high-frequency oscillators that are available for use with vehicles. This consequently reduces the distance that can be monitored by the radar.